You have a dodgy connection to the thermostat mounted temp sensor. When the ECU gets no signal, or an implausible signal, the fan runs all the time as a safety measure.


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You have a dodgy connection to the thermostat mounted temp sensor. When the ECU gets no signal, or an implausible signal, the fan runs all the time as a safety measure.

That or one of the two fan relays is stuck on.

 

Oh no not dodgy relays again, they seem to be haunting me again haha. I'll start checking connections then. I tried it an hour ago and the fan didn't come on for about a minute from cold. It ran for about 20 seconds then went off again. Then nothing for a couple of minutes then on again. It's certainly a bit erratic.

 

Oh no not dodgy relays again, they seem to be haunting me again haha. I'll start checking connections then. I tried it an hour ago and the fan didn't come on for about a minute from cold. It ran for about 20 seconds then went off again. Then nothing for a couple of minutes then on again. It's certainly a bit erratic.

Std behaviour when the A/C is on.

 

or your aircon is switched on...

 

Really? The AC can do that? I never knew. To be honest I haven't checked and fingers are crossed it is. That would be a very nice result if it is only that.

 

The A/C matrix is in front of the engine rad and needs to be cooled when the A/C is on.
It won't over-cool the engine if the thermostat is working properly.

 

You were right it was the A/C. Turned it off and no fan. What a relief that was. No more fault finding I hope for a while. I only have one worry now that it takes a long time to warm up. About 20 minutes at stand still. From what I've read here it's either normal or the thermostat stuck open. I won't know for sure until I go for a drive I guess. Still that's for another day I think. Thanks for the advice on this one, it saved me a lot of bother.

 

20 minutes sounds about right for the 2.4; from a cold start till fully warm and only idling... in summer it'll take significantly less time

 

You need a new thermostat.
Do it NOW before the weather gets too cold.

 

Oh no really? Is that too long to warm up then? My pockets have really taken a hit lately. Still better now than later as I learnt with the cam belt. Would you stick to genuine parts for this or go aftermarket? I've read some don't last very long

 

It does take a long time to get warm at idle. Go for a drive and see if you can get a decent tempature

 

ECP do a decent quality stat for about £35 - I fitted one about 6 weeks ago - fits well and cured my constant cold-running issues.

 

Oh ok not sure what to do now. Maybe this extra info might help decide if I do have a problem. Last year I drove up to the lake district and accidentally, thanks to a sat nav issue ended up on top of a mountain. A hose blew off the radiator and I lost lots of water but thankfully I was right next to a stream so could refill and get to the camp site. I thought nothing of it at the time until now as there wasnt any reason for me to think something was that wrong. Now the fact it takes ages to warm up is something Ive not noticed before. The heaters in the car do get warm quickly though, so maybe that's an indication all is OK? But one thing I havent noticed ever before is that as soon as I start the engine, from cold, I can see the coolant being pumped into the header tank via the little tube next to the filler cap. Im not sure if this is right but to me it isnt. Makes me think that something is being bypassed or routed wrongly.

Does that point any closer to it being a dodgy thermostat or is all OK and Im just being overly paranoid after all my recent issues. Last thing I want to do is buy a new one and waste £78.

 

PS sorry about this problem being split over two threads.